1. Field of the Invention
This invention relates to systems and methods to increase electric voltage for residential, commercial, and industrial loads.
2. Description of the Related Art
Electricity for residential and industrial use is typically generated at an electric power generating station, and sent through transmission lines in an electricity grid to a distribution system, which carries the electricity to the consumer. In many parts of the world, electric power supply has not kept up with demand, often resulting in brownouts. A brownout is a drop in voltage in the electrical power supply, often resulting in dimming of lighting when the voltage sags. Brownout voltages sometimes drop enough to cause appliances or equipment to stop operating. Such appliances or equipment may sustain permanent damage as a result of the low voltage condition.
A brownout may be caused by (1) inadequate power generation, (2) insufficient power transmission capacity, and/or (3) insufficient power distribution capacity. Inadequate power generation and insufficient power transmission are easier to remedy than insufficient power distribution capacity. Both power generation demand and power transmission capacity can be calculated and fulfilled comparatively easily within fiscal budgets.
The main obstacle to providing sufficient power to consumers is insufficient power distribution capacity. The need for power distribution capacity cannot be easily planned for or economically implemented. Moreover, as the world population grows, and industrial participation in the world economy increases, the power distribution infrastructure will be increasingly strained or overloaded by the additional loads placed on it. The distribution problems can often be attributed to copper losses within the cabling that forms the distribution infrastructure.
A transformer transfers electrical energy from one circuit to another through inductively coupled conductors. A varying current in the first or primary windings creates a varying magnetic flux in the transformer's core, and thus a varying magnetic field through the secondary windings. If a load is connected to the secondary, an electric current will flow in the secondary windings and electrical energy will be transferred from the primary circuit through the transformer to the load. The ratio of the transformer is the number of turns in the secondary windings to the number of turns in the primary windings.
The solution to the power distribution problem often employed is to boost the incoming voltage to allow sensitive appliances to continue operating. One solution has been to use motor driven Variac type transformers that continuously adjust the voltage to the nominal voltage. However, this solution requires mechanical implementation that is prone to failure. A second solution has been to employ electronic solid-state boosters that continuously adjust the voltage to the nominal voltage. However, this solution is expensive and inefficient. A third solution is to use relay switched transformers. The problem with this solution is that the mechanical contacts are prone to failure with the high currents being switched. Finally, manually switched transformers have been tried. This solution is undesirable because it requires a person in attendance, and the transformer can be inadvertently left in the boost position. Each of the above solutions of the past has problems of safety, efficiency, cost, complexity and/or reliability. The solutions of the past that utilize transformers and switching perform the switching on the transformer secondary windings side, where disadvantageous high currents are present. There is also a disadvantageous interruption of current with such prior solutions during the switching period.
Pub. No. U.S. 2009/0046490 proposes an IGBT/FET-based energy savings device, system and method wherein a predetermined amount of voltage below a nominal line voltage and/or below a nominal appliance voltage is saved. Pub. No. U.S. 2009/0051344 proposes a TRIAC/SCR-based energy savings device, system and method wherein a predetermined amount of voltage below a nominal line voltage and/or below a nominal appliance voltage is saved. Pub. No. U.S. 2009/0200981 proposes a system and method for providing constant loading in AC power applications wherein at least one turn-on point of at least one half cycle of a modulating sine wave is determined, at least one turn-off point of the at least one half cycle of the modulating sine wave is determined, and at least one slice located between the at least one turn-on point and the at least one turn-off point in removed. Pub. No. U.S. 2010/003155 proposes a power supply for IGBT/FET drivers that provides separated, isolated power to each IGBT/FET driver.
U.S. Pat. No. 6,489,742 proposes a motor controller that includes power conveyance to an induction motor with a digital signal processor that calculates and optimizes supply of current for existent motor loading from a power supply and main voltage through a control element. Pub. No. U.S. 2010/0117588 proposes a motor controller for maximizing the energy savings in an AC induction motor at every load wherein the motor is calibrated at two or more load points to establish a control line, which is then programmed into a non-volatile memory of the motor controller.
The above discussed U.S. Pat. No. 6,489,742 and Pub. Nos. U.S. 2009/0046490; 2009/0051344; 2009/0200981; 2010/0033155; and 2010/0117588 are incorporated herein by reference for all purposes in their entirety.
A need exists for a safe, inexpensive, reliable, and efficient way to boost voltage that places a minimum additional load on the electricity grid.